Heat producing devices, such as printed circuit boards, often contain heat producing components, such as processors or voltage regulators. A thermal plane may be provided in combination with the heat producing devices to form an assembly to aid in the removal of heat, typically by providing additional conductive pathways to disperse the heat. Typically, air cooling and liquid cooling systems are used in open environments where the heat may be dissipated to the surroundings. In certain instances, the heat producing components may operate under transient modes of increased heat production where high heat dissipations are expected over short durations. The transient mode may exceed the capacity of the cooling system, unless the cooling system is sized for the worst-case transient response, which results in over capacity for steady-state operation.